Win update service reset to default by itself

I have computers running in XP Pro SP3. Im running an application which often conflicts with windows updates; therefore, I need to turn off automatic update. I disabled and stopped the service but the service changes to automatic by itself. I have asked the network administrator to setup a group policy to disable AU and it didn't work. I then tried to change the registery by following the steps on this link http://support.microsoft.com/kb/892... but the AU still comes back.

I log in to a domain with local administrator privilage, and this happens right after I updated from SP2 to SP3. Virus and spyware is not a concern as these computers dont have access to websites other than the ones that requires the application to run on. Any ideas would be great. Thanks in advance.

The information on Computing.Net is the opinions of its users. Such
opinions may not be accurate and they are to be used at your own risk.
Computing.Net cannot verify the validity of the statements made on this
site. Computing.Net and Compnet Ventures, LLC hereby disclaim all responsibility
and liability for the content of Computing.Net and its accuracy.